1. Field of the Invention
The present invention relates to a segment with a heating and cooling device and a mold using the segment mentioned above, which can preferably produce a composite insulator consisting of a core member and a housing member arranged around the core member, the housing member being constructed by a trunk portion and a shed portion.
2. Related Art Statement
Generally, various types of composite insulators have been known as an insulation member to be used for a shell of, for example, a bushing. FIG. 4 is a schematic view showing one embodiment of a known composite insulator. In FIG. 4, a composite insulator 51 comprises a core member 52 made of, for example, FRP tube, and a housing member 55 arranged around the core member 52. Moreover, the housing member 55 is constructed by a trunk portion 53 and a plurality of shed portions 54 arranged outwardly from the trunk portion 53. Further, fitting members 56 are arranged at both end portions of the core member 52. In the known composite insulator 51 mentioned above, the housing member 55 constructed by the trunk portion 53 and the shed portion 54 is preferably made by a silicone rubber.
The known composite insulator 51 having the construction mentioned above is produced by using a mold 61 as shown in FIG. 5. In FIG. 5, the mold 61 comprises a through-hole 62 through which the core member 52 made of the FRP tube is arranged, and a shed forming recess 63 for forming the shed portion 54. The mold 61 may be formed by an integral type or a divided type. Moreover, a heating device 66 such as a heater or the like for heating the mold 61 is arranged outside of the mold 61.
In FIG. 5, the core member 52 is set in the through-hole 62 by means of the fitting members 56. Since an outer diameter of the core member 52 is smaller than an inner diameter of the through-hole 62, a space for forming the trunk portion 53 can be arranged between the core member 52 and the mold 61. Then, an elastic polymer material, preferably a silicone rubber, is supplied from an elastic polymer material inlet 65 into the space between the core member 52 and the mold 61. After that, the supplied elastic polymer material is cured by heating the mold 61 by means of the heating device 66. Finally, the mold 61 is moved, for example, downwardly to obtain the composite insulator 51.
In the producing method mentioned above, it is possible to produce the composite insulator. However, since the heating device 66 is arranged outside of the mold 61, a drawback occurs in the case of heating the elastic polymer material, such that it takes a lot of time for heating from a temperature at a start of the heating operation to a predetermined curing temperature by means of the heating device 66. Moreover, in the producing method mentioned above, it is necessary to set the next composite insulator in the mold 61 after the elastic polymer material is cured at the curing temperature and the current composite insulator is detached from the mold 61. In this case, if a temperature of the mold 61 is higher than for example room temperature, the elastic polymer material starts to be cured. Therefore, when the elastic polymer material for the next composite insulator is supplied in the mold 61, it is necessary to cool the mold 61 to a temperature such as room temperature at which the elastic polymer material is not cured at all. In the producing method mentioned above, since a heat capacity of the mold 61 is large, a drawback occurs such that it takes a lot of time to cool the mold 61. Further, since the elastic polymer material to be heated is arranged apart from the heating device 66, a drawback occurs such that a temperature distribution during the heating operation is not uniform. Therefore, in the known method of producing the composite insulator, the time necessary for producing the composite insulator increases and producing efficiency becomes decreases.